Optical disk drive, method for formatting optical disk, and optical disk

ABSTRACT

An optical disk drive (B 10 ) initializes a magneto-optical disk (A 10 ) by dividing a recording area (A 13 ) into zones and by assigning a logical address to each of the zones.  
     The disk drive includes an EEPROM ( 14 ) containing a medium management table providing, as rewritable assignment-order data, an order in which the logical address is assigned to each zone. A CPU ( 11 ) writes initializing data onto each of the zones while assigning them with the logical address in accordance with the assignment order data provided by the medium management table. Further, the CPU ( 11 ) changes the order of assigning the logical addresses depending on the number of defective sectors detected and/or the number of retries made during the initialization, rewrites the assignment order data on the medium management table accordingly, and writes the changed assignment order data onto medium management information (A 11 ) on the magneto-optical disk (A 10 ).

CROSS REFERENCE TO RELATED APPLICATION

[0001] This is a continuation of International Application No.PCT/JP00/04915 filed Jul. 21, 2000.

TECHNICAL FIELD

[0002] The present invention relates to an optical disk drive forphysically formatting e.g. magneto-optical disks, a method forformatting an optical disks, and the optical disk as the object of thephysical formatting.

BACKGROUND ART

[0003] As shown in FIG. 15, a conventional magneto-optical disk Aincludes a multiple of lands and grooves for recording data. The landsand grooves are conceptually divided circumferentially of the disk at apredetermined angle into a number of address-assignable sectors.Further, the magneto-optical disk A is conceptually divided by physicalformatting into zones each including a series of sectors. The number ofzones depends on the capacity and kind of the magneto-optical disk. Forexample, the magneto-optical disk of a 640 MB capacity is divided intoeleven zones, whereas the magneto-optical disk of a 1.3 GB capacity isdivided into eighteen zones as shown in FIG. 16. The lands, grooves andsectors are not illustrated in the accompanying drawings. In practicalapplication the lands and grooves are often formed in helix.

[0004] Each of the zones in the magneto-optical disk A is given alogical address at the time of physical formatting. The logical addressis assigned in order from the radially inward through the outward sideor vise versa, i.e. from the radially outward through the inward side,of the magneto-optical disk A according to industrial standards. Forexample, in the magneto-optical disks of 230 MB, 540 MB and 640 MBcapacities, the logical address is assigned from the radially mostinward zone through the most outward zone. On the other hand, in themagneto-optical disks of 1.3 GB capacity, as shown in FIG. 16, thelogical address is assigned from the radially most outward zone throughthe most inward zone. As described, the order in which the logicaladdress assignment is made is an industrial standard set fourth for eachkind and capacity of the magneto-optical disks, and therefore cannot bealtered arbitrarily.

[0005] Next, description will be made for a series of proceduresexecuted when a command is received from a host C for writing data ontoa magneto-optical disk A. When loaded with a magneto-optical disk A, therecorder/player B in FIG. 15 calls up a medium type identifier 100 toread medium management information A1 which is pre-recorded on themagneto-optical disk A, and identifies the type of the disk.

[0006] An address converter 110 makes reference to a medium managementtable 120, reads data about the order of logical address assignmentwhich is the standard set forth for each type of the disks, and based onthis data obtains the order of the logical address for each zone. Forexample, if the magneto-optical disk is of the 230 MB, 540 MB or 640 MBcapacity, the address converter 110 recognizes that the logical addressis assigned from the radially most inward zone through the most outwardzone. On the other hand, if the magneto-optical disk is of the 1.3 GBcapacity, the address converter 110 recognizes that the logical addressis assigned from the radially most outward zone through the most inwardzone.

[0007] Further, the, address converter 110, upon reception of logicaladdresses specified by the host C, makes reference to the mediummanagement table 120, reads data about the number of sectors in eachzone which is a standard set forth for each type of the disks, andobtains preliminary physical addresses based on the read data. Thesepreliminary physical addresses will be formal addresses if there is nodefective sector found in any zones of the magneto-optical disk A, or ifdefective sectors are found to have no influence on the addressassignment during the obtainment of the physical addresses. The addressconverter 110 makes reference to PDL (Primary Defect List, to bedescribed later) and SDL (Secondary Defect List, to be described later)contained in the medium management information A1, and checks if therewill be an influence on the preliminary physical addresses.

[0008] Here, comparison is made between FIG. 18 and FIG. 19: when adefective sector is detected in a zone during the physical formatting ofa magneto-optical disk A, the defective sector is skipped by the step ofwriting initializing data, and this zone which includes the defectivesector is extended into a spare zone in order to provide a predeterminednumber of flawless sectors by using a spare sector available in thespare zone. The physical address of the defective sector is recorded inthe medium management information A1 for management of the medium. Sucha defect, i.e. a defect in which a logical address can be assigned whileskipping defective sectors, is called primary defect. A set of addressesof the defective sectors that fall into the category of the primarydefect is called PDL.

[0009] On the other hand, compare FIG. 18 and FIG. 20: when a defectivesector is detected in a zone while writing data, the data is writtenonto another sector in the spare zone, in place of the defective sector.Then, the physical address of the defective sector and the physicaladdress of the spare sector which replaced the defective sector arerecorded onto the medium management information A1 for the sake ofaddress conversion. Such a defect, i.e. a defect in which a replacingspare sector can be specified by address conversion, is called secondarydefect. A set of addresses of the defective sectors that fall into thecategory of the secondary defect is called SDL.

[0010] Specifically, when a magneto-optical disk A includes primarydefects, the address converter 110 makes reference to the PDL, shifts agiven address according to the number of the primary defects, andthereby obtain a correct physical address. On the other hand, when thereare secondary defects, and their preliminary physical addresses areincluded in the SDL, the address converter 110 makes reference to theSDL, and thereby obtain physical addresses of replacing sectors. Thus,the address converter 110 converts logical addresses given by the host Cinto correct physical addresses.

[0011] With the above, data sent from the host C together withspecifying addresses are temporarily stored in an unillustrated databuffer provided in the recorder/player B. A data reading/writing section140 writes the data according to the physical addresses obtained by theaddress converter 110. When the writing of data is complete, the datareading/writing section 140 reports the completion of the operation tothe host C. Such data writing is performed for the number of blocksspecified by the host C.

[0012] Next, description will be made about access to a magneto-opticaldisk A. Generally, the host C, operating on the basis of an OS(Operating System) which provides file managing capabilities, controlsthe location of files stored on the magneto-optical disk A via therecorder/player B. For this purpose, file management information A2which indicates file location is stored at a head portion of the zonesassigned with logical addresses on the magneto-optical disk A. Whenevera file is read, made, updated or deleted on the magneto-optical disk A,reference is made to the file management information A2 and theinformation is updated. Therefore, the head portion of the zones on themagneto-optical disk A is the area that is accessed most frequently.

[0013] When files are added to the magneto-optical disk A, writing offile data is made in an ascending order of logical addresses, i.e. froma zone having a smaller logical address through a zone having a largerlogical address. For example, in magneto-optical disks of the 230 MB,540 MB and 640 MB capacities, the logical address assignment is madefrom the radially most inward zone through the most outward zone, andthus the file data is written from the inward toward the outward side.On the contrary, in magneto-optical disks of the 1.3 GB capacity, asshown in FIG. 16, the logical address is assigned from the radially mostoutward zone through the most inward zone, and thus the file data iswritten from the outward to the inward side.

[0014] As will be understood, in a magneto-optical disk A, it is veryrare that each zone is accessed equally, and it is very usual thataccess is concentrated on zones having the smallest logical addresses,in reading/writing of data.

[0015] Next, description will be made about an operation for physicallyformatting a magneto-optical disk A. When loaded with a magneto-opticaldisk A, the recorder/player B calls up the medium type identifier 100 toread medium management information A1 which is pre-recorded on themagneto-optical disk A, and identifies the type of the disk. When thephysical formatting is requested from the host C to the recorder/playerB, the address converter 110 makes reference to the medium managementtable 120, reads data about the order of logical address assignmentwhich is a standard set forth for each type of the disks, as well as thefirst and the last physical addresses for each zone based on the readdata, and obtains a physical address for each zone.

[0016] A physical formatter 130 writes initializing data, within therange from the first through the last addresses obtained for each zone,in the order from a zone having the smallest logical address through azone having the largest logical address. When there is a failure inwriting the initializing data, a recovery section 150 makes a retryregarding the writing of the initializing data until a predeterminednumber of retries is reached. If the writing is not successful withinthe predetermined number of retries, this sector is treated asdefective, and the physical address of the defective sector istentatively stored in the form of PDL in a memory 160. This formattingprocedure is executed to all sectors in all zones which are to beinitialized.

[0017] When the number of defective sectors detected during theformatting procedure has exceeded a predetermined limit, the physicalformatter 130 cancels the formatting procedure and reports a disk errorto the host C. On the other hand, when the number of defective sectorsdid not exceed the limit, the physical formatter 130 copies the PDL,which has been stored in the memory 160 during the formatting, onto themedium management information A1 on the magneto-optical disk A, andreports a successful completion of the formatting to the host C. Theabove is a conventional physical formatting procedure.

[0018] Now, consider a case in which the host C sends a data writingcommand accompanied with address specification in the form of logicaladdress. The address converter 110 converts the given logical addressinto a physical address, obtains physical addresses of the first and thelast sectors onto which the data is to be written, and further, checksif there is any defective sectors within the range specified by theaddresses. If there is no defective sector within the range, each ofnecessary steps such as erasing/writing/verifying procedures isperformed one time to every sector, continuously from the first to thelast sectors specified by the addresses for the data writing.

[0019] However, if there are defective sectors within the specifiedrange, the data writing must be made while skipping these defectivesectors. Therefore, the erasing/writing/verifying procedures arerepeated as many times as the number of regions fragmented by thedefected sectors. In other words, each of the erasing/writing/verifyingprocedures is performed to the plurality of regions, at a cost of idlingrotations of the magneto-optical disk A, resulting in a prolonged datawriting time.

[0020] Likewise, consider a case in which the host C sends a datareading command accompanied with address specification in the form oflogical address. The address converter 110 converts the given logicaladdress into a physical address, obtains physical addresses of the firstand the last sectors from which the data is to be read, and further,checks if there is any defective sectors within the range specified bythe addresses. If there is no defective sector within the range, areading procedures is performed one time, continuously from the first tothe last sectors specified by the addresses for the data reading.

[0021] However, if there are defective sectors within the specifiedrange, the data reading must be made while skipping these defectivesectors. Therefore, the reading procedure is repeated as many times asthe number of regions fragmented by the defected sectors. In otherwords, the reading procedure is performed to the plurality of regions,at a cost of idling rotations of the magneto-optical disk A, resultingin a prolonged data reading time.

[0022] With the above, as described earlier, there is the filemanagement information A2 at a zone that has the smallest logicaladdress, and whenever a file is read or written, reference is made tothe file management information A2 and the information is updated.Therefore, access is concentrated on the zone having the smallestlogical address. If this zone contains many defective sectors, a longtime must be spent for updating the file management information A2 everytime the host C requests file writing or reading, and this results indelayed response to the host C.

[0023] There is another problem: whenever a file is accessed for readingor writing, the address converter 110 searches the PDL and the SDL inthe medium management information A1 in order to convert logicaladdresses specified by the host C into physical addresses. This searchis executed on the basis of an unillustrated control program stored inthe recorder/player B. The PDL lists a number of sectors for whichaddress shifting is necessary, whereas the SDL contains physicaladdresses of replacement sectors. Obviously therefore, a long time mustbe spent for the search if there are many defective sectors, since thePDL and the SDL contain many addresses.

[0024] The prolonged search time spent by the control program results inextra waiting time due to disk idling rotations. Especially, accordingto a recent recorder/player B which features a high-speed disk rotation,an amount of time necessary for the disk to make a single turn isshorter than an amount of time necessary for searching the PDL or theSDL. As a result, performance decrease is apparent when using therecorder/player B.

[0025] There is still another problem. Specifically, when the host Crequests the recorder/player B to read or write data, and if there is afailure in the reading/writing, the recovery section 150 performs aretry with regard to the data reading/writing. When this retry issuccessful and therefore the reading/writing is completed, as comparedto a case where there is no failure in the procedure, the amount of timeneeded for the procedure is longer by the amount of time spent for theretry procedure. Due to increased capacity, magneto-optical disks A inrecent years have an increasingly narrow track pitch. This has increasedprobability of executing the retry procedure and there is a tendencythat the number of retries is increasing. As a result, the amount oftime spent for the retries and the number of retries have a significantinfluence on the performance of the recorder/player B.

[0026] As described, it is known that the zone having the smallestlogical address is accessed very frequently since it includes the filemanagement information A2. A large number of retries performed in thiszone poses a problem of delayed response to the host C after the host Csends a writing command or a reading command.

[0027] Further, in a magneto-optical disk A in which logical addressesare assigned alternately to the land and the groove, there is usually noproblem in reading/writing data whether the first logical address isgiven to a land or a groove. However, according to the conventionalmagneto-optical disk A, the zone having the smallest logical address isunchangeably fixed to either one of the land and the groove. Assume asituation, for example, in which there are more defective sectors in thelands than in the grooves. If it is possible to change so that logicaladdress assignment is started from the grooves, then it becomes possibleto speed up access during the referencing and updating of the filemanagement information A2. However, if the zone which has the smallestlogical address is unchangeably provided by the lands due to thestandard, it has not been possible to improve on the access time byreducing access time for the referencing and updating of the filemanagement information A2.

[0028] In addition, although the magneto-optical disk A tends to have alarger capacity, it can be said that users rarely use up all of thecapacity, and in great majority of cases only a portion of the entirecapacity is used. Even under such a situation where use of the capacityby the users is limited, the current physical formatting procedureprovides formatting for the entire capacity. This has created a problemthat, for example, as long as 18 minutes have to be spent for physicallyformatting a 1.3 GB magneto-optical disk for its entire capacity,resulting in an inconvenience to the users.

DISKLOSURE OF THE INVENTION

[0029] It is therefore an object of the present invention to provide anoptical disk drive, a method for formatting an optical disk, and theoptical disk, capable of allowing more efficient access to the opticaldisk as well as improving on convenience of use.

[0030] A first aspect of the present invention provides an optical diskdrive for initializing an optical disk by dividing a recording area intozones and by assigning a logical address to each of the zones. Theoptical disk drive comprises: a medium management table providing, asrewritable assignment-order data, an order in which the logical addressis assigned to each zone; a formatter performing the initializationwhile assigning the logical address to each zone in accordance with theassignment order data provided by the medium management table; and anaddress assignment order changer changing the order of assigning thelogical addresses depending on a situation in the initializationperformed by the formatter, rewriting the assignment order data on themedium management table accordingly, and writing the changed assignmentorder data onto the optical disk.

[0031] A second aspect of the present invention provides an optical diskdrive for initializing an optical disk by dividing a recording area intozones and by assigning a logical address to each of the zones. Theoptical disk comprises: a medium management table providing, asrewritable assignment-order data, an order in which the logical addressis assigned to each zone; a formatter performing the initializationwhile assigning the logical address to each zone in accordance with theassignment order data provided by the medium management table; and anaddress' assignment order changer changing the order of assigning thelogical addresses according to a request from a host requesting theformatter of the formatting and within a range of the zones specified bythe host, rewriting the assignment order data on the medium managementtable accordingly, and writing the changed assignment order data ontothe optical disk.

[0032] A third aspect of the present invention provides an optical diskdrive for initializing an optical disk by dividing a land and a grooveinto address-assignable recording areas as unit sectors, grouping therecording areas into zones each including a series of the sectors, andassigning each of the zones with a logical address. The optical diskdrive comprises: a medium management table providing, as a re-writableassignment order data, an order according to which the logical addressis assigned to each zone; a formatter performing the initializationwhile assigning the logical address to each of the zones in accordancewith the assignment order data provided by the medium management table,and detecting a defective sector to which the address is unassignable;and an address assignment order changer changing the logical addressassignment order into an ascending order in which one of the zones foundby the formatter to include the fewest defective sectors is placed ontop of the order, rewriting the assignment order data on the mediummanagement table accordingly, and writing the changed assignment orderdata onto the optical disk.

[0033] A fourth aspect of the present invention provides an optical diskdrive for initializing an optical disk by dividing a land and a grooveinto address-assignable recording areas as unit sectors, grouping therecording areas into zones each including a series of the sectors, andassigning each of the zones with a logical address. The optical diskdrive comprises: a medium management table providing, as a re-writableassignment order data, an order according to which the logical addressis assigned to each zone; a formatter performing the initializationwhile assigning the logical address to each of the zones in accordancewith the assignment order data provided by the medium management table,and counting the number of retries attempted for the initialization; andan address assignment order changer changing the logical addressassignment order into an ascending order in which one of the zones foundby the formatter to have the smallest retry count is placed on top ofthe order, rewriting the assignment order data on the medium managementtable accordingly, and writing the changed assignment order data ontothe optical disk.

[0034] According to a preferred embodiment, the formatter forms thezones from one side toward another of a radially outward side and aradially inward side of the recording area, assigning the logicaladdress alternately to the land and the groove in each of the zones. Theaddress assignment order changer makes the change so that the logicaladdress assignment begins from whichever one of the lands and thegrooves including a fewer defective sectors in the zone located mostclosely to said one side.

[0035] According to another preferred embodiment, the formatter formsthe zones from one side toward another of a radially outward side and aradially inward side of the recording area, assigning the logicaladdress first to all of the lands or all of the grooves in each of thezones. The address assignment order changer makes the change so that thelogical address assignment begins from whichever of the lands and thegrooves including a fewer defective sectors in the zone located mostclosely to said one side.

[0036] According to still another preferred embodiment, the addressassignment order changer makes the change so that the logical address isnot assigned to any of the zones including the defective sectors beyonda predetermined quantity.

[0037] According to still another preferred embodiment, thepredetermined quantity of the defective sectors is set by a notificationfrom the host requesting the initialization at the time of theformatting.

[0038] According to still another preferred embodiment, the formatterforms the zones from one side toward another of a radially outward sideand a radially inward side of the recording area, assigning the logicaladdress alternately to the land and the groove in each of the zones. Theaddress assignment order changer making the change so that the logicaladdress assignment begins from whichever one of the lands and thegrooves having a smaller retry count in the zone located most closely tosaid one side.

[0039] According to still another preferred embodiment, the formatterforms the zones from one side toward another of a radially outward sideand a radially inward side of the recording area, assigning the logicaladdress first to all of the lands or all of the grooves in each of thezones. The address assignment order changer makes the change so that thelogical address assignment begins from whichever of the lands and thegrooves having a smaller retry count in the zone located most closely tosaid one side.

[0040] According to still another preferred embodiment, the addressassignment order changer makes the change so that the logical address isnot assigned to any of the zones having the retry count beyond apredetermined limit.

[0041] According to still another preferred embodiment, thepredetermined limit of the retry count is set by a notification from thehost requesting the initialization at the time of the formatting.

[0042] A fifth aspect of the present invention provides a method forinitializing an optical disk by dividing a recording area on the opticaldisk into zones and by assigning a logical address to each of the zones.The method comprises: a step of having a medium management tableprovide, as rewritable assignment-order data, an order in which thelogical address is assigned to each zone; a formatting step ofperforming the initialization while assigning the logical address toeach zone in accordance with the assignment order data provided by themedium management table; and a step of address assignment order change,of changing the order of assigning the logical addresses depending on asituation in the initialization performed by the formatting step,rewriting the assignment order data on the medium management tableaccordingly, and writing the changed assignment order data onto theoptical disk.

[0043] A sixth aspect of the present invention provides a method forinitializing an optical disk by dividing a recording area on the opticaldisk into zones and by assigning a logical address to each of the zones.The method comprises: a step of having a medium management tableprovide, as rewritable assignment-order data, an order in which thelogical address is assigned to each zone; a formatting step ofperforming the initialization while assigning the logical address toeach zone in accordance with the assignment order data provided by themedium management table, and a step of address assignment order change,of changing the order of assigning the logical addresses according to arequest from a host requesting of the formatting and within a range ofthe zones specified by the host, rewriting the assignment order data onthe medium management table accordingly, and writing the changedassignment order data onto the optical disk.

[0044] A seventh aspect of the present invention provides a method forinitializing an optical disk by dividing a land and a groove on theoptical disk into address-assignable recording areas as unit sectors,grouping the recording areas into zones each including a series of thesectors, and assigning each of the zones with a logical address. Themethod comprises: a step of having a medium management table provide, asa re-writable assignment order data, an order according to which thelogical address is assigned to each zone; a formatting step ofperforming the initialization while assigning the logical address toeach of the zones in accordance with the assignment order data providedby the medium management table, and detecting a defective sector towhich the address is unassignable; and a step of address assignmentorder change, of changing the logical address assignment order into anascending order in which one of the zones found by the formatting stepto include the fewest defective sectors is placed on top of the order,rewriting the assignment order data on the medium management tableaccordingly, and writing the changed assignment order data onto theoptical disk.

[0045] An eighth aspect of the present invention provides a method forinitializing an optical disk by dividing a land and a groove on theoptical disk into address-assignable recording areas as unit sectors,grouping the recording areas into zones each including a series of thesectors, and assigning each of the zones with a logical address. Themethod comprises: a step of having a medium management table provide, asa re-writable assignment order data, an order according to which thelogical address is assigned to each zone; a formatting step ofperforming the initialization while assigning the logical address toeach of the zones in accordance with the assignment order data providedby the medium management table, and counting the number of retriesattempted for the initialization;

[0046] and a step of address assignment order change, of changing thelogical address assignment order into an ascending order in which one ofthe zones found by the formatting step to have the smallest retry countis placed on top of the order, rewriting the assignment order data onthe medium management table accordingly, and writing the changedassignment order data onto the optical disk.

[0047] A ninth aspect of the present invention provides an optical diskto be initialized by dividing a recording area into zones and byassigning a logical address to each of the zones. The optical diskcontains an order in which the logical address is assigned to each zone,as rewritable assignment-order data in an area different from therecording area. The order of assigning the logical addresses is changeddepending on a situation in the initialization.

[0048] A tenth aspect of the present invention provides an optical diskto be initialized by dividing a recording area into zones and byassigning a logical address to each of the zones. The optical diskcontains an order in which the logical address is assigned to each zone,as rewritable assignment-order data in an area different from therecording area. The order of assigning the logical addresses is changedwithin a specified range of the zones according to a request made at atime of the initialization.

[0049] An eleventh aspect of the present invention provides an opticaldisk to be initialized by dividing a recording area into zones and byassigning a logical address to each of the zones. The optical diskcontains an order in which the logical address is assigned to each zone,as rewritable assignment-order data in an area different from therecording area. The order of assigning the logical addresses is changedinto an ascending order in which one of the zones found to include thefewest defective sectors to which the address was unassignable duringthe initialization is placed on top of the order.

[0050] A twelfth aspect of the present invention provides an opticaldisk to be initialized by dividing a recording area into zones and byassigning a logical address to each of the zones. The optical diskcontains an order in which the logical address is assigned to each zone,as rewritable assignment-order data, in an area different from therecording area, the order of assigning the logical addresses beingchanged into an ascending order in which the zone found to have thesmallest retry count attempted during the initialization will be on topof the order.

[0051] According to the present invention, when formatting e.g. anoptical disk, it is possible to change the order in which logicaladdresses are assigned to the zones. Therefore, it becomes possible toassign the logical addresses in the most preferred order depending on asituation of the recording area on the optical disk or on a fileaccessing method used by the OS, enabling efficient access to each ofthe zones thus formatted.

[0052] Specifically, it becomes possible that the zone given thesmallest logical address, that is accessed always and frequently, isprovided by the zone including the fewest defective sectors or havingthe smallest retry count. As a result, it becomes possible to speed upthe access by concentrating the access on those zones which requireleast possible time for detecting defective sectors or performingretries.

[0053] Further, when there is such a request as to physically formatonly a part of the full capacity of a magneto-optical disk, it has nowbecome possible to assign logical addresses only to zones in a rangespecified by the request. This makes possible to complete the formattingin a shorter time than required for formatting for the full capacity,achieving a magneto-optical disk and a method of formatting which areconvenient to the users. Obviously, if there is such a request as tophysically format for the full capacity of the magneto-optical disk, itis possible to do so.

[0054] Other objects, characteristics, and advantages of the presentinvention will become clearer from the following description ofembodiments to be presented with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0055]FIG. 1 is a block diagram illustrating a first embodiment of thepresent invention.

[0056]FIG. 2 is a schematic diagram illustrating a magneto-optical diskin FIG. 1.

[0057]FIG. 3 is a diagram showing a DDS (Disk Definition Structure) inFIG. 2.

[0058]FIG. 4 is a functional block diagram of a controller in FIG. 1.

[0059]FIG. 5 is a diagram showing a structure of a medium managementtable.

[0060]FIG. 6 is a flowchart according to the first embodiment.

[0061]FIG. 7 is a continuation of the flowchart from FIG. 6.

[0062]FIG. 8 is a continuation of the flowchart from FIG. 6.

[0063]FIG. 9 is a flowchart according to a second embodiment.

[0064]FIG. 10 is a continuation of the flowchart from FIG. 9.

[0065]FIG. 11 is a continuation of the flowchart from FIG. 9.

[0066]FIG. 12 is a flowchart according to the third embodiment.

[0067]FIG. 13 is a continuation of the flowchart from FIG. 12.

[0068]FIG. 14 is a continuation of the flowchart from FIG. 12.

[0069]FIG. 15 is a block diagram illustrating a conventional procedureof physically formatting a magneto-optical disk.

[0070]FIG. 16 is a diagram illustrating a conventional magneto-opticaldisk of a 1.3 GB capacity.

[0071]FIG. 17 is a diagram showing a DDS in FIG. 16.

[0072]FIG. 18 is a diagram illustrating a zone without defect.

[0073]FIG. 19 is a diagram for describing a PDL and a primary defect.

[0074]FIG. 20 is a diagram for describing a SDL and a secondary defect.

BEST MODE FOR CARRYING OUT THE INVENTION

[0075] Hereinafter, a first embodiment of the present invention will bedescribed with reference to FIG. 1 through FIG. 8.

[0076] As shown in FIG. 1, the first embodiment of the present inventionuses a magneto-optical disk A10 as the optical disk, a recorder/playerB10 as the optical disk drive, and a personal computer C10 as a hostwhich directs formatting as well as reading/writing of data. Thepersonal computer C10, operating conventionally on the basis of an OS(Operating System) which provides file managing capabilities, does nothave any new essential characteristics, and therefore will not bedescribed or illustrated in specific details.

[0077] The magneto-optical disk A10 is provided by e.g. MO disks, ofdifferent capacities such as 230 MB, 540 MB, 640 MB, and 1.3 GB. Themagneto-optical disk A10 has no physical differences from conventionalones, and includes a multiple of lands and grooves (not illustrated)serving as a recording area A13 for storing data. Conceptually, themagneto-optical disk A10 has a number of sectors each made up of afragmented division of the land or groove. The lands and the grooves aregrouped into zones each including a series of sectors, by the physicalformatting to be described later. Generally, in a 640 MB magneto-opticaldisk for example, the entire recording area is divided into elevenzones. In a 1.3 GB magneto-optical disk, the entire recording area isdivided into eighteen zones. The zones include a different number ofsectors. Alternatively however, the zones maybe so made as to includethe same number of sectors.

[0078] The magneto-optical disk A1 has more areas in its recordingsurface. Specifically, there are a couple of areas, one being moreoutward and the other being more inward of the recording area A13. Theseextra areas are used for storing medium management information A11. Oneof the zones in the recording area A13 stores file managementinformation A12. FIG. 1 and FIG. 2 show a 1.3 GB magneto-optical diskA10 as an example, in which the file management information A12 isstored in the radially most inward zone of the recording area A13. Thisarrangement is different from the standard arrangement shown in FIG. 15and FIG. 16, and is a result of change performed on the basis ofsituation in the physical formatting or in response to a request fromthe personal computer C10. Note that FIG. 1 and FIG. 2 only show anexample.

[0079] The medium management information A11 includes a DDS illustratedin FIG. 3, as well as a PDL and an SDL. In particular, the DDS includesallocation order data in its byte numbers 40-57. The allocation orderdata indicates an order according to which logical addresses areassigned to the zones. The allocation order data can be altereddepending upon situations in the physical formatting to be describedlater and upon request from the personal computer C10. The filemanagement information A12 indicates addresses for locating files storedin the recording area A13 as well as file sizes. Whenever a file isread/written on the magneto-optical disk A10, reference and update aremade to the file management information A12. For this reason, the zoneincluding the file management information A12 is accessed mostfrequently. Further, the file management information A12 is stored at azone that has the smallest logical address.

[0080] As shown in FIG. 1, the recorder/player B10 includes a controller2, an optical head 3, a magnetic head 4, and a motor driving circuit 5.The controller 2 includes a CPU 11, a RAM 12, a ROM 13, an EEPROM 14 andan interface circuit 15. These CPU 11, RAM 12, ROM 13, EEPROM 14 and theinterface circuit 15 are interconnected via a bus line 16. The bus line16 includes a data bus, an address bus and a control signal bus.

[0081] The recorder/player B10, which works in accordance with variouscommands from the personal computer C10, performs physical formatting ofa magneto-optical disk A10, and performs reading/writing of files if themagneto-optical disk A10 is already physically formatted. The controller2 controls the optical head 3, the magnetic head 4, and the motordriving circuit 5 under the direction from the personal computer C10.The optical head 3 and the magnetic head 4 make access to the unitrecording areas (sectors) of the magneto-optical disk A10, under thecontrol provided by the controller 2. The motor driving circuit 5,controlled by the controller 2, drives a motor for turning themagneto-optical disk A10 and motors for moving the optical head 3 andthe magnetic head 4.

[0082] The CPU 11 provides control over the entire controller 2. The RAM12 provides the CPU 11 with a work area for storing various data. TheROM 13 stores programs for the CPU 11 to operate. The EEPROM 14 stores avariety of information, including a medium management table to bedescribed later with reference to FIG. 5.

[0083] The controller 2 can be illustrated as in a functional diagram inFIG. 4, and includes a medium type identifier 21, an address converter22, a medium management table 23, a physical formatter 24, an addressassignment order changer 25, a data reading/writing section 26, arecovery section 27, and a memory 28. Specifically, the CPU 11 providesthe medium type identifier 21, the address converter 22, the physicalformatter 24, the address assignment order changer 25, the datareading/writing section 26, and the recovery section 27. The RAM 12provides the memory 28. The EEPROM 14 provides the medium managementtable 23.

[0084] The medium type identifier 21 reads the medium managementinformation A11 from the magneto-optical disk A10, and identifies thetype of the disk.

[0085] The address converter 22, which is called up when the personalcomputer C10 requests reading/writing of files or data at specifiedlogical addresses, makes reference to the medium management table 23,the medium management information All and the file managementinformation A12 on the magneto-optical disk A10, and obtains physicaladdresses.

[0086] The medium management table 23 stores, as shown in FIG. 5,various kinds of information set forth for each type of the disks. Thisinformation includes the logical address assignment order data, and thisassignment order data in this medium management table 23 is changedaccordingly as changes are made to the medium management informationA11.

[0087] The physical formatter 24, assigns a logical address to each zonein accordance with the assignment order data stored in the mediummanagement table 23, and at the same time, writes an initializing dataonto the first sector through the last sector of each zone, in the orderfrom a zone having the smallest logical address through a zone havingthe largest logical address, thereby performing the physical formatting.During the physical formatting, the physical formatter 24 detectsdefective sectors which fall into the category of primary defect, i.e.those sectors which do not accept address assignment, and counts a totalnumber of defective sectors for each zone. The number of defectivesectors is represented by an average for each zone; however, the numbermay be a simple accumulation for each zone. If the writing ofinitializing data is not successful, the physical formatter 24 has therecovery section 27 try the writing of initializing data (this is calledretry procedure), and counts a number of retries attempted. Here again,the number of retries may be represented by a ratio, i.e. a count for azone vs. a total count for all the zones, or may be a simpleaccumulation for each zone. Physical addresses and a quantity of thedefective sectors, and the number of retries attempted are storedtemporarily in the memory 28.

[0088] The address assignment order changer 25 rewrites the logicaladdress assignment order data so that the logical address assignmentwill start from the zone found to include the fewest defective sectorsduring the physical formatting. Further, the address assignment orderchanger 25 can rewrite the logical address assignment order data so thatthe logical address assignment will start from a zone experienced thefewest retries during the physical formatting. Still further, theaddress assignment order changer 25 can rewrite the logical addressassignment order data in accordance with a request made by the personalcomputer C10 at the time of the physical formatting. During the above,there is no need for assigning the logical addresses to all the zones,but the logical addresses may be assigned only to the zones specified bythe personal computer C10.

[0089] The data reading/writing section 26 performs reading/writing offiles or data in accordance with the physical addresses obtained by theaddress converter 22.

[0090] The recovery section 27 performs the retry until a predeterminednumber of retries are reached, when the physical formatter 24 fails towrite initializing data.

[0091] Next, an operation performed for physically formatting amagneto-optical disk A10 will be described with reference to a flowchartgiven in FIG. 6 through FIG. 8.

[0092] First, when the magneto-optical disk A10 is loaded into therecorder/player B10, the CPU 11 reads the medium management informationA11 on the magneto-optical disk A10 (S10).

[0093] The CPU 11 then looks up the assignment order data which isstored in the DDS on the medium management information A11, andaccordingly changes assignment order data on the medium management table(S11).

[0094] Thereafter, the CPU 11 accepts a “start physical formatting”command from a personal computer C10 functioning as the host (S12), andchecks if the command from the host includes a direction that specifiesan arbitrary order of logical addresses (S13).

[0095] If the given command does not specify the order of logicaladdresses (S13: NO), the CPU 11 makes another check if the command fromthe host limits zones to which the logical addresses are to be assigned(S14).

[0096] If the command does not include the limit to the zones (S14: NO),the CPU 11 begins its procedure for the physical formatting by readingthe changed assignment order data on the medium management table andcalculating a logical address for each zone in accordance with the givenorder of assignment (S15).

[0097] Next, the CPU 11 writes initializing data onto the zones,starting from the zone which has been assigned with the smallest of thecalculated logical addresses through the zone assigned with the largest(S16) In each zone, a logical address is assigned to each sector as wellas initializing data written onto each sector, whereby each zone isphysically formatted.

[0098] If the process finds no defective sectors that fall into thecategory of primary defect (S17: NO), i.e. if all of the initializingdata writing attempts have been successful, then the CPU 11 checks ifthe writing of initializing data has been completed for all of the zones(S18).

[0099] When the writing has been complete for all of the zones (S18:YES), the CPU 11 checks if there is any retry counts stored in the RAM12 (S19). Description will be given later as to how the retry counts arestored in the RAM 12.

[0100] When retry counts are found in the RAM 12 (S19: YES), the CPU 11further checks if the RAM 12 stores physical addresses of defectivesectors (S20). Description will be given later as to how the physicaladdresses of defective sectors a restored in the RAM 12.

[0101] When physical addresses of defective sectors are found in the RAM12 (S20: YES), the CPU 11 stores the physical addresses of the defectivesectors in the form of PDL in the medium management information A11(S21).

[0102] Then, the CPU 11 changes the order of assigning the logicaladdresses according to which the original assignment was made (S22).This change in the logical address assignment order is performed in thefollowing way:

[0103] For example, take a case of a 1.3 GB magneto-optical disk A10.The original assignment order data specifies, as shown in FIG. 16, thatlogical addresses be assigned from radially most outward zone throughthe most inward zone. Now, assume that retry procedures were performedduring the process. Then, the logical addresses are reassigned in theorder starting from a zone which has the smallest retry count through azone which has the largest retry count, and the assignment order data ischanged accordingly. At an extreme case, as shown in FIG. 2, the logicaladdresses are assigned from the radially most outward zone toward theradially most inward zone. Obviously, the assignment order in FIG. 2 canbe changed to such an order as shown in FIG. 16, or the logicaladdresses can be assigned in a random order not following the physicalorder in which zones are located.

[0104] Now, take another case in which defective sectors are detectedwhile logical addresses are assigned according to the originalassignment data. In this case, the logical addresses are reassigned inthe order starting from a zone which includes the fewest defectivesectors through a zone which has the largest number of defectivesectors, and the assignment order data is changed accordingly. Hereagain, the resultant order can be just as in the examples given in theprevious paragraph.

[0105] It should be noted here that these two procedures, i.e. anassignment data changing procedure based on the number of retries and anassignment data changing procedure based on the number of defectivesectors, are executed selectively.

[0106] Now, assume further, that the original assignment of the logicaladdresses was started from a land or from a groove in each zone. Forexample, assume that a logical address was assigned first to a land,then to a groove, and then to a land, and then to a groove and so on, inalternation. In this case, the assignment order data will be changed sothat the logical address assignment will be started from either a landor a groove, i.e. the group having a smaller retry count or includingfewer defective sectors. For example, the order can be changed contraryto the above, so that the logical address is assigned first to a groove,then to a land, and then to a groove, then to a land and so on.

[0107] Alternatively, assume that the original assignment of the logicaladdresses was started from lands or from grooves in each zone. Forexample, assume that the logical address was assigned first to a land,then to another land, . . . and then to a groove and then to anothergroove and so on. In this case, the assignment order data will bechanged so that either the lands or the grooves having a smaller retrycount or including fewer defective sectors will be the first to beassigned with the logical addresses. For example, the order can bechanged contrary to the above, so that the logical addresses areassigned first to the grooves, and then to the lands.

[0108] After changing the logical address assignment order as describedabove, the CPU 11 rewrites the assignment order data contained in themedium management information A11 accordingly as the change was made(S23).

[0109] Further, the CPU 11 also rewrites the assignment order datacontained in the medium management table accordingly as the change wasmade (S24).

[0110] Finally, the CPU 11 reports the host about a successfulcompletion of the physical formatting (S25), and ends the physicalformatting procedure. With the above, the file management informationA12 which is to be located at the smallest address and closer to thehead of the entire recording area A13, will be placed in the zone whichhas the smallest retry count or including the fewest defective sectors,and further, either in the lands or in the grooves which haveexperienced a fewer retries or which include fewer defective sectors,within this particular zone.

[0111] In step S20, when the RAM 12 does not store any physicaladdresses of defective sectors (S20: NO), the CPU 11 executes step S22and changes the logical address assignment order only on the basis ofthe retry count.

[0112] In step S19, when the RAM 12 does not store any retry counts(S19: NO), i.e. when there was no defective sectors found and thus noretry procedure was performed, the CPU 11 brings the process down tostep S25, since there is no need for changing the logical addressassignment order.

[0113] In step S18, when the writing of initializing data has not beencomplete for all of the zones (S18: NO), then the CPU 11 brings theprocess back to step S15 to continue with the writing of initializingdata for the remaining zones.

[0114] In step S17, when the writing of initializing data was notsuccessful (S17: YES), the CPU 11 executes the retry procedure therebyattempting the writing of initializing data again (S26).

[0115] During the retry procedure, the CPU 11 counts the number ofretries attempted, and when the retry count exceeds the predeterminedthreshold value (S27: YES), the CPU 11 determines that the unitrecording area in process of the retry procedure is a defective sectorof the primary defect category, and then stores the address of thedefective sector in the RAM 12 (S28) The physical address of thedefective sector thus stored in the RAM 12 will be used in steps S20 andS21. The retry count is accumulated for each zone. The number of retriesspent for detecting the defective sector is not included in theaccumulation for the zone. Alternatively however, the number may beincluded, in which case the RAM 12 will also store the retry count.

[0116] Further, the CPU 11 checks if the number of defective sectors hasexceeded a predetermined maximum limit (S29).

[0117] When the number of defective sectors has exceeded thepredetermined maximum limit during the retry procedure (S29: YES), theCPU 11 reports to the host that a disk error has occurred (S30), cancelsthe physical formatting procedure, and ends the process.

[0118] On the other hand, when the number of defective sectors is notgreater than the predetermined maximum limit (S29: NO), the CPU 11brings the process back to S18.

[0119] In step S27, when the retry procedure is successful within thepredetermined number of retries given as the threshold value (S27: NO),i.e. when the sector is not detected as defective, the CPU 11 thenrecords a retry count, i.e. the number of retries which was necessaryuntil the retry was finally become successful, in the RAM 12 (S31), andbrings the process back to S18. The retry count stored in the RAM 12 inthis step will be used in step S19.

[0120] In step S14, when the command from the host includes a limitationon the zones (S14: YES), the CPU 11 changes the logical addressassignment data (S32) so that the logical addresses will be assignedonly to the specified zones. Accordingly, the change will be made alsoto the logical address assignment order data included in the mediummanagement table (S33). For example, take a case that the user specifiesin a command a physical formatting of a 1.3 GB magneto-optical disk A10only for a half of its capacity instead of the full 1.3 GB capacity. Insuch a case, the assignment data will be changed so that physicaladdresses will be assigned only to zones accounting for a half of the1.3 GB capacity. The magneto-optical disk A10 thus formatted becomesavailable for reading/writing of files and data, but only by using partof the full potential capacity. Thereafter, the CPU 11 brings theprocess to step S15.

[0121] In step S13, if the command from the host includes a request fora specific order of logical addresses (S13: YES), the CPU 11 changes thelogical address assignment order (S32) so that the logical addresseswill be assigned to the zones in the order specified by the command.Accordingly, the change will be made also to the logical addressassignment order data included in the medium management table (S33). Forexample, take the case in FIG. 16, in which the original order oflogical address assignment is from the radially most outward zonethrough the radially most inward zone. If the user selects a command andthereby specifies that the assignment order be reversed, then the neworder of logical address assignment is from the radially most inwardzone through the radially most outward zone, making possible to obtain amagneto-optical disk A10 which is formatted in a way different from theway it normally is.

[0122] Therefore, when reading/writing of files is performed to amagneto-optical disk A10 that is physically formatted according to thefirst embodiment, the file management information A12 which is alwaysreferred to and then updated is located in the zone which includes theleast number of defects. As a result, it becomes possible to guaranteethe highest possible probability for such procedures aserasing/writing/verifying as well as reading to be completed at thefirst attempt. It addition, it becomes possible to concentrate theaccess on the zones which requires the least possible time for detectionof defective sectors or execution of retries, thereby speeding up thefile access.

[0123] Further, when there is such a request from the host as tophysically format only a part of the full capacity of a magneto-opticaldisk A10, it has now become possible to assign logical addresses only tozones in a range specified by the request. This makes possible tocomplete the formatting in a shorter time than required for formattingfor the full capacity, achieving a magneto-optical disk A10 and a methodof formatting which are convenient to the users. In addition, theachieved order of logical address assignment is highly efficient in viewof file management by the OS.

[0124] Next, a second embodiment will be described.

[0125] The second embodiment is similar to the first embodiment, and canbe illustrated in the same drawings of FIG. 1 through FIG. 5. However,there is a slight difference from the first embodiment in the physicalformatting procedure, which will be described with reference to aflowchart given in FIG. 9 through FIG. 11. Note that the flowchartcontains same steps as in the first embodiment. These steps will beidentified by the same step numbers and not be described again.

[0126] A major difference in the second embodiment from the firstembodiment lies in that steps S13 and S14 are replaced by steps S40 andS41, and new steps S42 and S43 are added accordingly. Specifically, ifthe command from the host includes an upper limit to the number ofdefective sectors allowed per zone (S40: YES), the CPU 11 set the upperlimit to the number of the defective sectors (S41) on a register or inthe RAM 12, according to the command, before bringing the process downto S15. If the command from the host does not include the upper limit tothe number of defective sectors per zone (S40: NO), the process simplygoes down to S15, as in the case S14: NO.

[0127] Thereafter, in S29, even if the number of defective sector is notgreater than the maximum tolerable limit (S29: NO), the CPU 11 furtherchecks if the number of the defective sectors exceeds the upper limitset in step S41 (S42).

[0128] When the number of defective sectors has exceeded the upper limit(S42: YES), the CPU 11 cancels the initial data writing to the currentzone, assigns no logical address to the zone, and makes the zoneunavailable for use (S43) Then, the CPU 11 brings the process to S18.Specifically, even if the number of defective sectors in all of thezones to be formatted is within a given maximum tolerable range, a zoneis excluded if it includes more defective sectors than specified by thehost. This makes possible to speed up file access.

[0129] On the other hand, in step S42, when the number of defectivesectors is not greater than the upper limit (S42: NO), the CPU 11 simplybrings the process to step S18.

[0130] Thus, according to the second embodiment, the same advantages canbe enjoyed as in the first embodiment, and in addition, it becomespossible to exclude zones that have a large number of defective sectorsand therefore tend to slow down the access, according to a request bythe user. This makes possible to make a magneto-optical disk A10 of arequired quality for a specific use, and to speed up the file access ingeneral.

[0131] For instance, when a magneto-optical disk A10 is to be used for arecording/playing purpose which would not allow any defective sectorsper zone, the upper limit can be set to zero at the time of physicalformatting, so that a stable recording/playing can be guaranteed.

[0132] Next, a third embodiment will be described.

[0133] The third embodiment is similar to the first embodiment, and canbe illustrated also in the same drawings of FIG. 1 through FIG. 5.However, there is a slight difference from the first embodiment in thephysical formatting procedure, which will be described with reference toa flowchart given in FIG. 12 through FIG. 14. Note that the flowchartcontains same steps as in the first embodiment. These steps will beidentified by the same step numbers and not be described again.

[0134] A major difference in the third embodiment from the firstembodiment lies in that steps S13 and S14 are replaced by steps S50 andS51, and new steps S52 and S53 are added accordingly. Specifically, ifthe command from the host includes an upper limit to the number ofretries per zone (S50: YES), the CPU 11 set the upper limit to thenumber of retries (S51) on a register or in the RAM 12, according to thecommand, before bringing the process down to S15. If the command fromthe host does not include the upper limit to the number of retries perzone, the process simply goes down to S15, as in the case S14: NO.

[0135] Thereafter, in S27, even if the retry procedure is successfulwithin the given retry count set by the threshold value (S27: NO), theCPU 11 further checks if the accumulated retry count for the zoneexceeds the upper limit set in step S51 (S52).

[0136] When the number of retries has exceeded the upper limit (S52:YES), the CPU 11 cancels the initial data writing to the current zone,assigns no logical address to the zone, and makes the zone unavailablefor use (S53). Then, the CPU 11 brings the process to S18. Specifically,even if the number of retries in the entire area to be formatted is notgreater than the threshold value, a zone is excluded if its retry counthas exceeded the upper limit specified by the host. This makes possibleto speed up file access.

[0137] On the other hand, in step S52 when the retry count is notgreater than the upper limit (S52: NO), the CPU 11 stores the retrycount in the RAM 12 (S31), and then brings the process to step S18.

[0138] Thus, according to the third embodiment, the same advantages canbe enjoyed as in the first embodiment, and in addition, it becomespossible to exclude zones which have a high probability of receiving theretry procedure again and again, according to a request from the user.This makes possible to make a magneto-optical disk A10 of a requiredquality for a specific use, and to speed up the file access in general.

[0139] For instance, when a magneto-optical disk A10 is to be used for arecording/playing purpose which would not allow any retries per zone,the upper limit can be set to zero at the time of physical formatting,so that a very stable recording/playing can be guaranteed.

[0140] It should be noted that the present invention is not limited tothe embodiments described above.

[0141] For example, the recording disk may not be limited to the MOs,but can include MDs and a variety of iD-format magneto-optical disks.Further, the present invention is applicable to other kinds of diskssuch as optical disks of the phase-change type, the write-once type andsoon, including for example DVDs and CD-ROMs, as well as to magneticdisks such as hard disks and floppy disks.

[0142] Further, the physical formatting may not only be made by the userwith the personal computer C10, but also be made during manufacturingprocess of the magneto-optical disk when the magneto-optical disk 10 isshipped as formatted.

[0143] The operations provided by the CPU 11 of the recorder/player B10may alternatively be performed by the CPU of the host personal computerC10.

[0144] The logical address assignment order data is stored in a blankspace in the DDS shown in FIG. 3. Alternatively, the “Group Type” of theDDS may be expanded from a single-byte space to be a plural-byte space,so that the assignment order data can be stored in some of the bytes.

[0145] Another alternative can be that a flag is set in the DDSindicating if the logical address assignment order has been changed, andwhen the flag is not up, a conventional standard is applied in theassignment of the logical addresses.

[0146] The recorder/player B10 can perform physical formatting and datareading/writing to such conventional magneto-optical disks as of 230 MB,540 MB, 640 MB and 1.3 GB capacities which contain unchangeableassignment order data as part of their medium management information,while maintaining control algorithm compatibility.

[0147] Generally, as shown in the medium management table in FIG. 5, ina magneto-optical disk A10, radially outward side has a higher turningspeed and a higher recording/playing frequency, and therefore isbelieved to have a greater access efficiency than radially inward side.Based on this, the logical address assignment order data may be changedso that the assignment is started from the radially most outward sidewhich has the highest recording/playing frequency. Since the access timefor a sector becomes shorter with the increase in the recording/playingfrequency, access speed to the file management information A12 stored insuch particular zone can be made more quickly.

[0148] Still further, the logical address assignment order data may bechanged so that the assignment is started from a zone that includes thelargest number of sectors per track to a zone that includes the fewestof them. When the magneto-optical disk A10 is turning at a constantspeed, the zone that has the largest number of sectors per tack has theshortest access time, and therefore, access to the file managementinformation A12 stored in such particular zones can be made morequickly.

[0149] This arrangement reduces a probability that the file managementinformation A12 is stored in a scattered manner in a plurality of zonesand therefore has to be accessed while skipping zones. Thus, thearrangement can further speeds up the access. In addition, when itbecomes necessary to find a replacement sector from unused spare sectorsin the subsequent zone in the process of making up a secondary defectduring reading/writing of a file or data, there is a low probabilitythat the access must be made by jumping over zones. This can also leadto a speedy access.

[0150] When reading/writing of files/data is performed to amagneto-optical disk A10 which is physically formatted already, theassignment order data included in the medium management information A11is copied onto the medium management table. In regard of this, for zoneswhich are not assigned with logical addresses, there can be anarrangement that the order for such zones is indicated as “0” in theassignment order data, and these zones are not given converted physicaladdresses. With this arrangement, for example, it becomes possible toexclude zones which would require an unreasonably long time inreading/writing of files/data due to too many defective sectors. Thisprovides an advantage that music, images and other data that must beprocessed as a continuous string of a certain length can berecorded/played without halt.

What is claimed is:
 1. An optical disk drive for initializing an opticaldisk by dividing a recording area into zones and by assigning a logicaladdress to each of the zones, comprising: a medium management tableproviding, as rewritable assignment-order data, an order in which thelogical address is assigned to each zone; a formatter performing theinitialization while assigning the logical address to each zone inaccordance with the assignment order data provided by the mediummanagement table; and an address assignment order changer changing theorder of assigning the logical addresses depending on a situation in theinitialization performed by the formatter, rewriting the assignmentorder data on the medium management table accordingly, and writing thechanged assignment order data onto the optical disk.
 2. An optical diskdrive for initializing an optical disk by dividing a recording area intozones and by assigning a logical address to each of the zones,comprising: a medium management table providing, as rewritableassignment-order data, an order in which the logical address is assignedto each zone; a formatter performing the initialization while assigningthe logical address to each zone in accordance with the assignment orderdata provided by the medium management table; and an address assignmentorder changer changing the order of assigning the logical addressesaccording to a request from a host requesting the formatter of theformatting and within a range of the zones specified by the host,rewriting the assignment order data on the medium management tableaccordingly, and writing the changed assignment order data onto theoptical disk.
 3. An optical disk drive for initializing an optical diskby dividing a land and a groove into address-assignable recording areasas unit sectors, grouping the recording areas into zones each includinga series of the sectors, and assigning each of the zones with a logicaladdress, comprising: a medium management table providing, as are-writable assignment order data, an order according to which thelogical address is assigned to each zone; a formatter performing theinitialization while assigning the logical address to each of the zonesin accordance with the assignment order data provided by the mediummanagement table, and detecting a defective sector to which the addressis unassignable; and an address assignment order changer changing thelogical address assignment order into an ascending order in which one ofthe zones found by the formatter to include the fewest defective sectorsis placed on top of the order, rewriting the assignment order data onthe medium management table accordingly,. and writing the changedassignment order data onto the optical disk.
 4. An optical disk drivefor initializing an optical disk by dividing a land and a groove intoaddress-assignable recording areas as unit sectors, grouping therecording areas into zones each including a series of the sectors, andassigning each of the zones with a logical address, comprising: a mediummanagement table providing, as a re-writable assignment order data, anorder according to which the logical address is assigned to each zone; aformatter performing the initialization while assigning the logicaladdress to each of the zones in accordance with the assignment orderdata provided by the medium management table, and counting the number ofretries attempted for the initialization; and an address assignmentorder changer changing the logical address assignment order into anascending order in which one of the zones found by the formatter to havethe smallest retry count is placed on top of the order, rewriting theassignment order data on the medium management table accordingly, andwriting the changed assignment order data onto the optical disk.
 5. Theoptical disk drive according to claim 3, wherein the formatter forms thezones from one side toward another of a radially outward side and aradially inward side of the recording area, assigning the logicaladdress alternately to the land and the groove in each of the zones, theaddress assignment order changer making the change so that the logicaladdress assignment begins from whichever one of the lands and thegrooves including a fewer defective sectors in the zone located mostclosely to said one side.
 6. The optical disk drive according to claim3, wherein the formatter forms the zones from one side toward another ofa radially outward side and a radially inward side of the recordingarea, assigning the logical address first to all of the lands or all ofthe grooves in each of the zones, the address assignment order changermaking the change so that the logical address assignment begins fromwhichever of the lands and the grooves including a fewer defectivesectors in the zone located most closely to said one side.
 7. Theoptical disk drive according to claim 3, wherein the address assignmentorder changer makes the change so that the logical address is notassigned to any of the zones including the defective sectors beyond apredetermined quantity.
 8. The optical disk drive according to claim 7,wherein the predetermined quantity of the defective sectors is set by anotification from the host requesting the initialization at the time ofthe formatting.
 9. The optical disk drive according to claim 4, whereinthe formatter forms the zones from one side toward another of a radiallyoutward side and a radially inward side of the recording area, assigningthe logical address alternately to the land and the groove in each ofthe zones, the address assignment order changer making the change sothat the logical address assignment begins from whichever one of thelands and the grooves having a smaller retry count in the zone locatedmost closely to said one side.
 10. The optical disk drive according toclaim 4, wherein the formatter forms the zones from one side towardanother of a radially outward side and a radially inward side of, therecording area, assigning the logical address first to all of the landsor all of the grooves in each of the zones, the address assignment orderchanger making the change so that the logical address assignment beginsfrom whichever of the lands and the grooves having a smaller retry countin the zone located most closely to said one side.
 11. The optical diskdrive according to claim 4, wherein the address assignment order changermakes the change so that the logical address is not assigned to any ofthe zones having the retry count beyond a predetermined limit.
 12. Theoptical disk drive according to claim 11, wherein the predeterminedlimit of the retry count is set by a notification from the hostrequesting the initialization at the time of the formatting.
 13. Amethod for initializing an optical disk by dividing a recording area onthe optical disk into zones and by assigning a logical address to eachof the zones, comprising: a step of having a medium management tableprovide, as rewritable assignment-order data, an order in which thelogical address is assigned to each zone; a formatting step ofperforming the initialization while assigning the logical address toeach zone in accordance with the assignment order data provided by themedium management table; and a step of address assignment order change,of changing the order of assigning the logical addresses depending on asituation in the initialization performed by the formatting step,rewriting the assignment order data on the medium management tableaccordingly, and writing the changed assignment order data onto theoptical disk.
 14. A method for initializing an optical disk by dividinga recording area on the optical disk into zones and by assigning alogical address to each of the zones, comprising: a step of having amedium management table provide, as rewritable assignment-order data, anorder in which the logical address is assigned to each zone; aformatting step of performing the initialization while assigning thelogical address to each zone in accordance with the assignment orderdata provided by the medium management table; and a step of addressassignment order change, of changing the order of assigning the logicaladdresses according to a request from a host requesting of theformatting and within a range of the zones specified by the host,rewriting the assignment order data on the medium management tableaccordingly, and writing the changed assignment order data onto theoptical disk.
 15. A method for initializing an optical disk by dividinga land and a groove on the optical disk into address-assignablerecording areas as unit sectors, grouping the recording areas into zoneseach including a series of the sectors, and assigning each of the zoneswith a logical address, comprising: a step of having a medium managementtable provide, as a re-writable assignment order data, an orderaccording to which the logical address is assigned to each zone; aformatting step of performing the initialization while assigning thelogical address to each of the zones in accordance with the assignmentorder data provided by the medium management table, and detecting adefective sector to which the address is unassignable; and a step ofaddress assignment order change, of changing the logical addressassignment order into an ascending order in which one of the zones foundby the formatting step to include the fewest defective sectors is placedon top of the order, rewriting the assignment order data on the mediummanagement table accordingly, and writing the changed assignment orderdata onto the optical disk.
 16. A method for initializing an opticaldisk by dividing a land and a groove on the optical disk intoaddress-assignable recording areas as unit sectors, grouping therecording areas into zones each including a series of the sectors, andassigning each of the zones with a logical address, comprising: a stepof having a medium management table provide, as a re-writable assignmentorder data, an order according to which the logical address is assignedto each zone; a formatting step of performing the initialization whileassigning the logical address to each of the zones in accordance withthe assignment order data provided by the medium management table, andcounting the number of retries attempted for the initialization; and astep of address assignment order change, of changing the logical addressassignment order into an ascending order in which one of the zones foundby the formatting step to have the smallest retry count is placed on topof the order, rewriting the assignment order data on the mediummanagement table accordingly, and writing the changed assignment orderdata onto the optical disk.
 17. An optical disk to be initialized bydividing a recording area into zones and by assigning a logical addressto each of the zones, containing: an order in which the logical addressis assigned to each zone, as rewritable assignment-order data in an areadifferent from the recording area, the order of assigning the logicaladdresses being changed depending on a situation in the initialization.18. An optical disk to be initialized by dividing a recording area intozones and by assigning a logical address to each of the zones,containing: an order in which the logical address is assigned to eachzone, as rewritable assignment-order data in an area different from therecording area, the order of assigning the logical addresses beingchanged within a specified range of the zones according to a requestmade at a time of the initialization.
 19. An optical disk to beinitialized by dividing a recording area into zones and by assigning alogical address to each of the zones, containing an order in which thelogical address is assigned to each zone, as rewritable assignment-orderdata in an area different from the recording area, the order ofassigning the logical addresses being changed into an ascending order inwhich one of the zones found to include the fewest defective sectors towhich the address was unassignable during the initialization is placedon top of the order.
 20. An optical disk to be initialized by dividing arecording area into zones and by assigning a logical address to each ofthe zones, containing order in which the logical address is assigned toeach zone, as rewritable assignment-order data, in an area differentfrom the recording area, the order of assigning the logical addressesbeing changed into an ascending order in which the zone found to havethe smallest retry count attempted during the initialization will be ontop of the order.